Contacts for AT&T Postmaster, AWS WAF, Azure WAF

Hi All,

We recently obtained our first /24 from the ARIN waiting list. We’ve been testing it out the past few weeks, and we’re finding that it’s blocked in a couple places. Geolocation data has already been updated with the major providers, and the range is not listed in any known blocklists.

I’m looking for contacts for the following. Please reach out off-list if you can assist. Thank you in advance!

  • AT&T Postmaster – getting 521 errors, already emailed ‘’ multiple times but no response.

  • AWS WAF – some sites that use awselb/2.0 are throwing a “403 Forbidden.” They work fine from an older IP. Product vendors are unable to resolve so far.

  • Azure WAF – one site is completely resetting our connection attempts. Works fine from an older IP. Product vendor is unable to resolve so far.

Vishal Malli

IT Systems Engineer

City of Manteca, CA